1. Field of the Invention
The present invention relates to a source driver capable of high speed charging and discharging.
2. Discussion of Related Art
A cellular phone, a tablet or a personal computer (PC), etc. have display units for displaying information to users. A display unit includes a display panel and circuitry, such as a source driver, a gate driver, a timing controller, etc., for driving the display panel, and the circuitry is implemented as silicon-based complementary metal-oxide semiconductor (CMOS) circuitry. The source driver generates a grayscale voltage corresponding to input digital bits and drives pixels included in the display panel. The timing controller and the source driver may be formed in separate chips or one chip according to a resolution and characteristics of the display panel.
An afterimage generated while a user is viewing a video, etc. is a factor by which the picture quality of a display is determined. A problem of a long-lasting afterimage, etc. results from a response speed of a display driver or each pixel of a display being slower than the speed of change in pixel data. To eliminate dizziness of a user of a virtual reality (VR) display which is attracting attention as a future display device, it is required to remarkably improve a frame rate compared to existing displays. To this end, it is necessary to develop a display driving method for a high response speed.
An operating speed of a source driver chip used for pixel data driving in an existing display driver integrated circuit (IC) is dependent on a slew rate of an output buffer for data driving. It is possible to increase a bias current to improve the slew rate. However, an increase in bias current leads to an increase in power consumption of the source driver chip and thus is not suitable for a mobile environment.